Properties

Label 2.2e4_7e2.8t6.2
Dimension 2
Group $D_{8}$
Conductor $ 2^{4} \cdot 7^{2}$
Frobenius-Schur indicator 1

Related objects

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Basic invariants

Dimension:$2$
Group:$D_{8}$
Conductor:$784= 2^{4} \cdot 7^{2} $
Artin number field: Splitting field of $f= x^{8} - 4 x^{7} + 7 x^{6} - 14 x^{4} + 14 x^{3} + 7 x^{2} - 18 x + 9 $ over $\Q$
Size of Galois orbit: 2
Smallest containing permutation representation: $D_{8}$
Parity: Odd

Galois action

Roots of defining polynomial

The roots of $f$ are computed in $\Q_{ 197 }$ to precision 5.
Roots:
$r_{ 1 }$ $=$ $ 12 + 74\cdot 197 + 187\cdot 197^{2} + 73\cdot 197^{3} + 4\cdot 197^{4} +O\left(197^{ 5 }\right)$
$r_{ 2 }$ $=$ $ 30 + 104\cdot 197 + 182\cdot 197^{2} + 107\cdot 197^{3} + 6\cdot 197^{4} +O\left(197^{ 5 }\right)$
$r_{ 3 }$ $=$ $ 51 + 31\cdot 197 + 41\cdot 197^{2} + 136\cdot 197^{3} + 120\cdot 197^{4} +O\left(197^{ 5 }\right)$
$r_{ 4 }$ $=$ $ 56 + 115\cdot 197 + 33\cdot 197^{2} + 54\cdot 197^{3} + 65\cdot 197^{4} +O\left(197^{ 5 }\right)$
$r_{ 5 }$ $=$ $ 59 + 152\cdot 197 + 74\cdot 197^{2} + 49\cdot 197^{3} + 85\cdot 197^{4} +O\left(197^{ 5 }\right)$
$r_{ 6 }$ $=$ $ 106 + 184\cdot 197 + 179\cdot 197^{2} + 75\cdot 197^{3} + 65\cdot 197^{4} +O\left(197^{ 5 }\right)$
$r_{ 7 }$ $=$ $ 122 + 68\cdot 197 + 16\cdot 197^{2} + 168\cdot 197^{3} + 177\cdot 197^{4} +O\left(197^{ 5 }\right)$
$r_{ 8 }$ $=$ $ 159 + 57\cdot 197 + 72\cdot 197^{2} + 122\cdot 197^{3} + 65\cdot 197^{4} +O\left(197^{ 5 }\right)$

Generators of the action on the roots $r_1, \ldots, r_{ 8 }$

Cycle notation
$(1,4,6,7,2,8,3,5)$
$(1,3,2,6)(4,5,8,7)$
$(1,2)(3,6)(4,8)(5,7)$
$(1,2)(4,7)(5,8)$

Character values on conjugacy classes

SizeOrderAction on $r_1, \ldots, r_{ 8 }$ Character values
$c1$ $c2$
$1$ $1$ $()$ $2$ $2$
$1$ $2$ $(1,2)(3,6)(4,8)(5,7)$ $-2$ $-2$
$4$ $2$ $(1,2)(4,7)(5,8)$ $0$ $0$
$4$ $2$ $(1,8)(2,4)(3,5)(6,7)$ $0$ $0$
$2$ $4$ $(1,6,2,3)(4,7,8,5)$ $0$ $0$
$2$ $8$ $(1,4,6,7,2,8,3,5)$ $-\zeta_{8}^{3} + \zeta_{8}$ $\zeta_{8}^{3} - \zeta_{8}$
$2$ $8$ $(1,7,3,4,2,5,6,8)$ $\zeta_{8}^{3} - \zeta_{8}$ $-\zeta_{8}^{3} + \zeta_{8}$
The blue line marks the conjugacy class containing complex conjugation.